An alleged rift has emerged between Philip Hammond, the British chancellor of the exchequer, and his cabinet colleague Liam Fox, the international trade secretary, over a key Brexit issue. While Hammond seems to think European citizens could still be allowed to move freely into the UK during the transition period between the end of Brexit negotiations and the UK’s full separation from the EU, Fox thinks not.

Downing Street has sought to clarify the position by stating that free movement will end in 2019 – though it remains unclear whether that’s possible.

The spat reveals a deeper philosophical conflict over how Brexit policy should be conducted by the government. For some ministers, a successful Brexit is one that limits negative consequences for the UK economy. For others, like Fox, it’s more important to “keep faith” with the referendum decision itself.

The issue of free movement is one dramatisation of the conflict. Another is what role to give to the European Court of Justice in the future Brexit settlement. This decision may also fall victim to an imperative to hold true to one of the defining themes of the Leave campaign. Prime Minister Theresa May herself echoed the mantras of that campaign in her Lancaster House speech in January when she declared “we will take back control over our laws and bring an end to the jurisdiction of the European Court of Justice in Britain”.

As a means of charting a course for the UK out of the EU, Fox and the prime minister are guilty of the sin of “originalism”.

“Originalism” is a concept that often crops up in the US. It refers to a belief that the Supreme Court’s sole function is to keep faith with the literal text of the constitution as it was written. The meaning of the constitution in 2017 should be the same as that intended by the original framers of the constitution back in 1787.

Hammond is not quite on the same page as Fox on free movement.PA

It’s an approach associated with a conservative right in the US. The aim is to ensure that an unelected judiciary does not extend legal rights such as access to abortion under the guise of interpreting the text of the constitution in light of changing times and circumstances.

Similarly, debates within the Christian church about recognising same-sex relationships get mired in a conflict between those who weaponise the text of the Bible as an unyielding and unchanged set of rules and others for whom the text is the beginning of a process of constant discovery of what it means to follow a particular faith.

Brexit orginalism

Now originalism is being practised as part of the Brexit debate. The difference, though, is that the Brexit schism is not based on the contested reading of a particular historical text. Instead, it centres on the interpretation of a historical event – the referendum held in June 2016.

Fox and various other figures have adopted the view that the government should not only implement the referendum result but also to “keep faith” with the reasons and rationales which apparently led voters to reject continuing EU membership.

But originalism is selective in its readings of the past. That the US constitution allowed its citizens not just to keep and bear arms but also keep slaves gets forgotten when it comes to trying to talk sense about gun control. The Bible’s list of abominations is deployed to deplore homosexuality, yet practices such as tattoos, long hair and eating seafood slip through the net.

In the context of Brexit, Fox picks control over borders as his article of faith. Meanwhile, he conveniently ignores that many voters also wanted Brexit to be a means of taking back control over trade.

In the week that President Trump signalled that the US and the UK might do a quick trade deal, Fox seemed remarkably relaxed about the idea that the UK might be forced to accept chlorine-washed chickens as part of a post-Brexit trade deal. Some Leave voters may have wanted the UK to have greater freedom to strike its own trade deals including with the US, but others were anxious about the effects of an increasingly globalised economy on their employment prospects. Fox’s originalism is just as selective as any other form.

Originalism is also an abandonment of judgement and responsibility. Politicians – government ministers and the Labour opposition – are behaving as if they have no choice but to give effect to a mandate enshrined and encoded in the referendum result regardless of whether there is any clarity as to the original intent of voters or of the consequences of implementing such an intention.

It’s time for politicians to drop the originalist pretence of keeping faith with the country. They should instead do the one thing the British system of parliamentary democracy is supposed to do – empower the representatives of the people to make decisions and to be accountable for them.

Brexit is a choice made in time and through time. It is a process that began with the referendum but doesn’t have to end there. Instead the prime minister faces a choice. Either she allows Brexit to be defined by an originalist and selective interpretation of the June 2016 referendum or she takes the June 2017 election as an instruction to govern in the country’s best interests. She must choose whether to be defined by the past or to define the future.